Dive dry with dr. Bill 602: Mating is dangerous... Just say no

Please register or login

Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.

Benefits of registering include

  • Ability to post and comment on topics and discussions.
  • A Free photo gallery to share your dive photos with the world.
  • You can make this box go away

Joining is quick and easy. Log in or Register now!

drbill

The Lorax for the Kelp Forest
Scuba Legend
Rest in Peace
Messages
22,824
Reaction score
6,061
Location
Santa Catalina Island, CA
# of dives
2500 - 4999
DIVE DRY WITH DR. BILL 602: MATING IS DANGEROUS... JUST SAY NO

August 24th was the 45th anniversary of my arrival on Catalina. On that day in 1969 I woke up aboard the dive boat "Golden Doubloon" and had my first look at the island. I thought it looked just like Greece where I had spent much of the previous summer free diving... except at that time there was no ouzo here on the island. I was with a group from Ron Merker's Aquatic Center in Newport Beach. It was to be my first day of SCUBA diving in an ocean since all my prior dives were in fresh water (sure could use some now). The three things I remember about those first dives were the magnificence of the island's giant kelp forests, the shovelnose guitarfish that descended with me on my first dive and the fact I was not eaten by a great white shark!

The landlord has pretty much left me alone all these years, although a group of tech divers from Hollywoodivers had an incredible encounter with one August 23rd while removing ghost nets from the wreck of the squid boat Infidel off our East End. They probably needed ouzo after that dive! So what did I do to celebrate my anniversary? No, no ouzo... why, of course, I did a night dive at Casino Point! DUI (diving under the influence is never a good thing). No sign of the landlord, but the water was full of worms rising to the surface to spawn.

Back when I was in junior high and high school, and our hormones were kicking in, teachers often told us that practicing procreation was fraught with danger. Boy, if they thought it was dangerous back then, what about today with diseases that can't be cured with a little shot! And when I was older Nancy Reagan pleaded with us to "just say no." Of course at that age I was way past such a response... but fortunately the women I met weren't! Sigh.

However, mating in the animal kingdom often entails the very serious "pastability" of death. Many species are not accustomed to close contact, and their mating rituals may be accompanied by fear that their mate may indulge in a little munching after mating. Of course I have done that, too... but only with a healthy food snack. Just ask the male praying mantis about the chances of losing his head after he succumbs to his lady's charms! Even the broadcast spawners for whom no contact is involved often have much to fear. The only time I see the Ophioderma brittle stars out in the open is at night when they come out from under their protective rocks and crawl up on top of the reef to mate. Just as quickly as they release their gametes, they tumble back down to safety so predators don't get to munch them.

Now for some reason this summer the kelp (or calico) bass have been unusually obnoxious... and numerous They love to follow my bright video lights so they can more easily see the poor blacksmith hiding in the reef and try to take them. This summer a poor young octopus jetted off the reef when highlighted by my lights... right into the jaws of a kelp bass. The calicos have even taken species they normally don't like such as young treefish. Why not long ago I filmed one grabbing a small lobster in its mouth and swimming off with the antennae sticking out. Wonder how that meal went? I usually remove the eat from the spiny tail when I eat them.

The bass have become so disturbing that I'm almost tempted to suggest Fish & Wildlife begin culling them. Of course I guess it just means that our dive park is doing exactly what it is supposed to do as a marine protected area (MPA). Kelp bass are generally reef associated fish that don't stray too far from their home turf. Unfortunately, the outer boundary of this MPA does little to protect the lobster population. At night they wander out to deeper waters in search of munchies... and many get caught by the hoop netters who (legally) set their traps just outside the dive park boundary when bug season begins.

But once again I digress. This week's column is not about lobster.. it is about the dangers of trying to mate. In the past I've thrilled my readers with tales of all the segmented worms I see rising off the reef and heading towards the surface. They seem to mistake my video lights for a full moon and rise up to cast their gametes in the water column in hopes that little worms will result. These worms are often not seen during daylight since they hide in the reef and under rocks. But when they get that "urge," they abandon all logic and sense and ascend. The higher they go, the farther the currents may take their youngsters... and who wants the kids hanging around any longer than necessary?

Well, the kelp bass that have learned to use my video lights to hunt blacksmith apparently are now applying this same deadly technique to the spawning worms. On several occasions this summer, I've followed the rising worms and placed them directly in my spotlight only to have a kelp bass rush up and swallow them whole! Now I'd much rather have a blacksmith than a slimy old worm, but I guess they wanted a bit more variety in their diet.

With two of the incidents I captured on film the bass may have inadvertently assisted in the reproductive effort. OK, so it was flash memory... who uses film these days? In these two occasions the bass did not completely swallow the entire worm. The posterior segments, which contain the gametes, were missed and entered the water column where the sperm or eggs they contained might find their opposite and fertilize. Of course in the situation where the entire worm was swallowed whole, it can forget about contributing its genes to the next generation!

Image caption: Spawning worm rising toward the surface and kelp bass swallowing it whole. Gulp! There go the gametes.


DDDB 602 worm taken by kelp bass sm.jpg
 
https://www.shearwater.com/products/swift/

Back
Top Bottom